Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the behavioral burden, and it does disclose meaningful traits: the type is stored by Fabrement and re-registered on every request rather than relying on a plugin, plus the archive-URL side effect for public types with hasArchive. It stops short of stating permissions, idempotency on slug collision, or whether registration is reversible.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core action and the key prerequisite, then the rules. Dense and mostly waste-free, though the telegraphic 'to dress with' phrasing and stacked arrow-style references cost a little readability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 12-parameter creation tool (output schema present, so return values need no explanation), the description covers the storage model, the mandatory prerequisite doc, sibling routing, and a parameter-interaction side effect. Minor gaps remain around failure modes (duplicate/reserved slug) and reversibility, which the schema's uniqueness note only partly covers.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description adds cross-parameter meaning the schema does not: that 'public' combined with 'hasArchive' produces an archive URL that must be dressed via other tools. That interplay is genuine semantic value beyond the per-field descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific verb ('Register a NEW custom post type') plus the resource, with concrete examples (Book, Project, Event). The emphasis on NEW cleanly distinguishes it from the sibling fabrement-update-post-type, and the storage/registration note differentiates it from any third-party plugin approach.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit sequencing is given: 'list-post-types first' before creating, and 'get-skill-doc {id:"content-model-contract"} — read it before the first call.' It also routes the agent onward for the archive case via save-archive-page + assign-template-archive, so the ordering of related tools is unambiguous.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.